Solar Cell And Photovoltaic Module

ABSTRACT

A solar cell and a photovoltaic module including the solar cell. The solar cell includes: a semiconductor substrate including a first surface and a second surface opposite to each other; a first dielectric layer located on the first surface; a first N+ doped layer located on a surface of the first dielectric layer; a first passivation layer located on a surface of the first N+ doped layer; a first electrode located on a surface of the first passivation layer; a second dielectric layer located on the second surface; a first P+ doped layer located on a surface of the second dielectric layer; a second passivation layer located on a surface of the first P+ doped layer; and a second electrode located on a surface of the second passivation layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/104,585, filed on Nov. 25, 2020, which claims priority to ChinesePatent Application No. 202011069475.8, filed on Sep. 30, 2020. All ofthe afore-mentioned patent applications are hereby incorporated byreference in their entireties.

TECHNICAL FIELD

The present disclosure relates to the field of solar cell technologies,and, in particular, to a solar cell and a photovoltaic module.

BACKGROUND

A solar cell is initially considered to be the cleanest andinexhaustible energy source theoretically. At present, with developmentof science and technology, the solar cell can be stably manufactured inlarge scale to supply energy, and therefore yield of the solar cell isrising year by year. With development of photovoltaic industry,improving conversion efficiency of the solar cell has become a goalpursued by photovoltaic enterprises. In order to achieve high efficiencyof solar cells, a variety of cell structures have been designed, e.g., apassivation contact structure formed by an ultra-thin tunnel oxide layerand a highly doped polysilicon layer prepared at the back side of thecell using tunnel oxide passivation contact (TOPCon) techniques, withadvantages of high efficiency, long service life, no LID and goodresponse to weak light, etc. In addition, in the existing solar cells, adouble-side solar cell can absorb light on both sides, which greatlyincreases photoelectric conversion efficiency of the cell per unit area,and therefore, it has attracted more and more attention of all circlesof the society.

At present, in a conventional N-type passivation contact solar cell, asubstrate is a N-type silicon, a P+-type doped layer is provided at afront side of the cell, and an ultra-thin silicon oxide layer and an N+heavily doped polycrystalline silicon layer are provided on a back sideof the cell. Passivation contact is generally provided at the back sideof the cell. To achieve the passivation contact at the front side of thecell or both sides of the cell, it is required to adopt ITO (atransparent conductive layer) at the front side of the cell, similar tothe Heterojunction with Intrinsic Thinlayer (HIT) cell structure, so asto solve lateral transmission problem of the ultra-thin polycrystallinesilicon. However, on the one hand, although ITO is a transparentconductive oxide, a certain light loss may be caused due to lightabsorption of ITO, affecting conversion efficiency of the cell; on theother hand, if ITO is used, the ITO may not be compatible with existinghigh-temperature production lines and high-temperature metallizationprocesses, and cost of upgrading the existing cell production lines isvery high.

SUMMARY

In view of this, a purpose of the present disclosure is to provide asolar cell and a photovoltaic module, which can alleviate a compromiserestriction between lateral transmission and light absorption of apolycrystalline silicon film when a passivation contact structure isapplied to the front side of the cell, increasing a short-circuitcurrent of the cell while achieving a high open-circuit voltage.

In order to achieve the purpose, the following technical solutions areprovided.

In a first aspect of the present disclosure, a solar cell is provided.The solar cell includes: a semiconductor substrate comprising a firstsurface and a second surface that are opposite to each other; a firstdielectric layer located on the first surface; a first N+ doped layerlocated on a surface of the first dielectric layer; a first passivationlayer located on a surface of the first N+ doped layer; a firstelectrode located on a surface of the first passivation layer; a seconddielectric layer located on the second surface; a first P+ doped layerlocated on a surface of the second dielectric layer; a secondpassivation layer located on a surface of the first P+ doped layer; anda second electrode located on a surface of the second passivation layer.

In an embodiment, the first dielectric layer includes at least one ofsilicon oxide, hafnium oxide, titanium oxide, silicon nitride, siliconoxynitride, or aluminum oxide; and the first dielectric layer has athickness in a range from 0.5 nm to 3 nm.

In an embodiment, the first N+ doped layer has a doping concentration ina range from 5×10¹⁹ cm⁻³ to 6×10²⁰ cm⁻³; and the first N+ doped layerhas a thickness in a range from 5 nm to 30 nm.

In an embodiment, the first passivation layer includes at least one ofsilicon nitride, silicon oxide, silicon oxynitride, or silicon carbide;and the first passivation layer have a thickness in a range from 70 nmto 180 nm.

In an embodiment, the second dielectric layer includes at least one ofsilicon oxide, hafnium oxide, titanium oxide, silicon nitride, siliconoxynitride, or aluminum oxide; and the second dielectric layer has athickness in a range from 0.5 nm to 3 nm.

In an embodiment, the first P+ doped layer has a doping concentration ina range from 5×10¹⁹ cm⁻³ to 6×10²⁰ cm⁻³; and the first P+ doped layerhas a thickness in a range from 80 nm to 300 nm.

In an embodiment, the second passivation layer includes at least one ofsilicon nitride, silicon oxide, silicon oxynitride, or silicon carbide;and the second passivation layer have a thickness in a range from 70 nmto 180 nm.

In an embodiment, the semiconductor substrate is an N-type semiconductorsubstrate, the first surface is a front surface of the semiconductorsubstrate, and the second surface is a back surface of the semiconductorsubstrate.

In an embodiment, at least one region on the surface of the first N+doped layer is further provided with a third dielectric layer and asecond N+ doped layer, the first electrode penetrates through the firstpassivation layer to be in contact with the second N+ doped layer, andthe at least one region on the surface of the first N+ doped layercorresponds to a region of the first electrode.

In an embodiment, the third dielectric layer includes at least one ofsilicon oxide, hafnium oxide, titanium oxide, silicon nitride, siliconoxynitride, or aluminum oxide; and the third dielectric layer has athickness in a range from 0.5 nm to 3 nm.

In an embodiment, the second N+ doped layer has a thickness in a rangefrom 50 nm to 150 nm.

In an embodiment, at least one region of the first N+ doped layer isformed as a thickened N+ doped region, the first electrode penetratesthrough the first passivation layer to be in contact with the thickenedN+ doped region, and the at least one region of the first N+ doped layercorresponds to a region of the first electrode.

In an embodiment, the thickened N+ doped region has a thickness in arange from 80 nm to 200 nm.

In an embodiment, the semiconductor substrate is a P-type semiconductorsubstrate, the first surface is a back surface of the semiconductorsubstrate, and the second surface is a front surface of thesemiconductor substrate.

In an embodiment, at least one region on the surface of the first P+doped layer is further provided with a fourth dielectric layer and asecond P+ doped layer, the second electrode penetrates through thesecond passivation layer to be in contact with the second P+ dopedlayer, and the at least one region on the surface of the first P+ dopedlayer corresponds to a region of the second electrode.

In an embodiment, the fourth dielectric layer includes at least one ofsilicon oxide, hafnium oxide, titanium oxide, silicon nitride, siliconoxynitride, or aluminum oxide; and the fourth dielectric layer has athickness in a range from 0.5 nm to 3 nm.

In an embodiment, the second P+ doped layer has a thickness in a rangefrom 50 nm to 150 nm.

In an embodiment, at least one region of the first P+ doped layer isformed as a thickened P+ doped region, the second electrode penetratesthrough the second passivation layer to be in contact with the thickenedP+ doped region, and the at least one region of the first P+ doped layercorresponds to a region of the second electrode.

In an embodiment, the thickened P+ doped region has a thickness in arange from 80 nm to 200 nm.

It should be noted that each of the above ranges of values includesendpoint values thereof.

In a second aspect of the present disclosure, a photovoltaic module isprovided. The photovoltaic module includes solar cells as mentionedabove, and at least part of the solar cells is connected to each otherin a splicing or stacking manner and sealed by an encapsulatingmaterial.

Compared with the prior art, the technical solutions provided by thepresent disclosure have at least the following beneficial effects:

The solar cell provided by the application includes a first dielectriclayer, a first N+ doped layer, a first passivation layer, and a firstelectrode on a first surface of the semiconductor substrate, and asecond dielectric layer, a first P+ doped layer, a second passivationlayer, and a second electrode formed on a second surface of thesemiconductor substrate. In this way, the effect of double-sidepassivation contact can be realized. With the aid of the substratematerial, a lower lateral transmission resistance can be achieved, thatis, the substrate material can be used to assist in the lateraltransmission of carriers, alleviating compromise restriction between thelateral transmission and the light absorption of the polycrystallinefilm when the passivation contact structure is applied to the front sideof the cell, increasing the open-circuit voltage and short-circuitcurrent, and avoiding the occurrence of the light absorption of theexisting ITO or thick polycrystalline silicon.

The photovoltaic module of the present disclosure includes solar cellsmentioned above, and has at least all the characteristics and advantagesof the solar cells described above, which will not be repeated here.

It should be understood that the above general description and thefollowing detailed description are only illustrative and do not limitthe present disclosure.

BRIEF DESCRIPTION OF DRAWINGS

In order to more clearly illustrate technical solutions of embodimentsof the present disclosure or the technical solutions in the related art,the accompanying drawings used in the embodiments or the related art arebriefly described below. The drawings described below are merely a partof the embodiments of the present disclosure. Based on these drawings,those skilled in the art can obtain other drawings without any creativeeffort.

FIG. 1 is a structural schematic diagram showing an N-type passivationcontact solar cell according to an exemplary embodiment of the presentdisclosure;

FIG. 2 is a structural schematic diagram showing an N-type passivationcontact solar cell according to another exemplary embodiment of thepresent disclosure;

FIG. 3 is a structural schematic diagram showing an N-type passivationcontact solar cell according to still another exemplary embodiment ofthe present disclosure;

FIG. 4 is a structural schematic diagram showing a P-type passivationcontact solar cell according to an exemplary embodiment of the presentdisclosure;

FIG. 5 is a structural schematic diagram showing a P-type passivationcontact solar cell according to another exemplary embodiment of thepresent disclosure; and

FIG. 6 is a structural schematic diagram showing a P-type passivationcontact solar cell according to still another exemplary embodiment ofthe present disclosure.

DESCRIPTION OF EMBODIMENTS

In order to better understand objects, technical solutions andadvantages of the present disclosure, the present disclosure is furtherdescribed in details with reference to the accompanying drawings andembodiments. It should be understood that the specific embodimentsdescribed here are only used to explain the present disclosure, but notto limit the present disclosure.

It should be understood that the term “and/or” used in the context ofthe present disclosure is to describe a correlation relation of relatedobjects, indicating that there may be three relations, e.g., A and/or Bmay indicate only A, both A and B, and only B.

It should be understood that the orientation terminologies, such as,“on” and “under”, described in the embodiments of the present disclosureare described according to the angle shown in the drawings, and shouldnot be construed as limiting the embodiments of the present disclosure.In addition, it should also be understood that when one element is “on”or “under” another element, the one element not only can be directly“on” or “under” another element, the one element can also be indirectly“on” or “under” another element through an intermediate element. Theterms “a”, “an”, “the” and “said” in a singular form in the embodimentsof the present disclosure and the appended claims are also intended toinclude plural forms thereof, unless indicated otherwise.

In order to overcome shortcomings of the prior art, the presentdisclosure provides a solar cell and a photovoltaic module including thesolar cell, in order to reduce light absorption loss, improve conversionefficiency of the cell, and increase an open-circuit voltage and ashort-circuit current of the cell.

In view of this, referring to FIG. 1 to FIG. 6, in some embodiments ofthe present disclosure, a solar cell is provided. The solar cellincludes: a semiconductor substrate including a first surface 10 and asecond surface 20 that are opposite to each other; a first dielectriclayer 101 located on the first surface 10; a first N+ doped layer 102located on a surface of the first dielectric layer 101; a firstpassivation layer 103 located on a surface of the first N+ doped layer102; a first electrode 104 located on a surface of the first passivationlayer 103; a second dielectric layer 201 located on the second surface20; a first P+ doped layer 202 located on a surface of the seconddielectric layer 201; a second passivation layer 203 located on asurface of the first P+ doped layer 202; and a second electrode 204located on a surface of the second passivation layer 203.

The first passivation layer 103 may be referred to as a firstanti-reflection layer, and the second passivation layer 203 may bereferred to as a second anti-reflection layer. To some extent, the firstpassivation layer 103 or the second passivation layer 203 may be used toachieve the anti-reflection effect. Generally in the art, a passivationlayer on the substrate mainly functions to passivate dangling bonds ofthe surface of the substrate and prevent recombination of carriers in asurface region. An anti-reflection layer may have partial passivationeffect, but as it is generally located on the passivation layer and isfar away from the surface of the silicon substrate, a main purpose ofthe anti-reflection layer is to adjust a refractive index of the overalllight-transmitting layer to achieve anti-reflection effect of increasinglight absorption. Meanwhile, the anti-reflection layer can furtherprotect the solar cell, improve weather resistance, and avoid efficiencydegradation caused by defects of the cell resulting from substances suchas oxygen, water, and metal ions entering the solar cell from theexternal environment. Therefore, when determining the structure of thesurface layer, the layer that is mainly used for passivation and closeto the surface of the silicon substrate is determined as a passivationlayer, and the layer that is located on the passivation layer isdetermined as an anti-reflection layer. For example, if the surfacestructure of the cell is silicon substrate surface/silicon oxide/siliconnitride, then the silicon oxide should be regarded as a passivationlayer, and the silicon nitride should be regarded as an anti-reflectionlayer. Similarly, in passivation structures of aluminum oxide/siliconnitride, silicon oxide/silicon oxynitride, and aluminum oxide/siliconoxynitride, the aluminum oxide and the silicon oxide should be regardedas a passivation layer, and the silicon nitride and the siliconoxynitride should be regarded as an anti-reflection layer. In thestructure of silicon oxide/aluminum oxide/silicon nitride, sincealuminum oxide contains high-density negative charges that play a roleof field passivation, the silicon oxide/aluminum oxide is regarded as apassivation layer, and the silicon nitride is regarded as ananti-reflection layer.

With the configuration of the embodiments of the present disclosure, adouble-side passivation contact effect can be achieved in the solarcell. With the aid of the substrate material, a lower lateraltransmission resistance can be achieved. That is, the material of thesubstrate can be used to assist in lateral transmission of carriers,alleviating a compromise restriction between lateral transmission andlight absorption of a polycrystalline silicon film when a passivationcontact structure is applied to the front side of the cell. Therefore,an open-circuit voltage and a short-circuit current can be increased,and a light absorption problem caused by the existing ITO or thickpolycrystalline silicon can be avoided.

The semiconductor substrate may be a crystalline silicon substrate(silicon substrate), such as a polycrystalline silicon substrate, amonocrystalline silicon substrate, or a monocrystalline silicon-likesubstrate, etc. The present disclosure does not limit the type of thesemiconductor substrate.

The first surface 10 may be a back surface of the semiconductorsubstrate, and the second surface 20 may be a front surface of thesemiconductor substrate. Alternatively, the first surface 10 may be afront surface of the semiconductor substrate, and the second surface 20may be a back surface of the semiconductor substrate.

In some embodiments of the present disclosure, the front surface of thesemiconductor substrate is a surface facing the sun, that is, a surfaceto be irradiated by sunlight, and the back surface of the semiconductorsubstrate is a surface facing away from the sun.

The semiconductor substrate may be P-doped or N-doped, that is, thesemiconductor substrate may be a P-type semiconductor substrate or anN-type semiconductor substrate. The solar cell according to theembodiments of the present disclosure may be a double-side passivationcontact P-type solar cell, or a double-side passivation contact N-typesolar cell.

Hereinafter, the double-side passivation contact N-type solar cell andthe double-side passivation contact P-type solar cell will be describedclearly and completely in combination with the drawings of the presentdisclosure. The described embodiments are merely part of the embodimentsof the present disclosure rather than all of the embodiments. All otherembodiments obtained by those skilled in the art based on theembodiments of the present disclosure without paying creative effortshall fall into the protection scope of the present disclosure.

[N-Type Solar Cell]

Referring to FIGS. 1-3, some embodiments of the present disclosureprovides a solar cell, i.e., a double-side passivation contact N-typesolar cell, including an N-type semiconductor substrate 1.

The N-type semiconductor substrate 1 includes a first surface 10 and asecond surface 20 that are opposite to each other. The first surface 10is a front surface of the semiconductor substrate, and the secondsurface 20 is a back surface of the semiconductor substrate.

A first dielectric layer 101, a first N+ doped layer 102, a firstpassivation layer 103, and a first electrode 104 are sequentiallyprovided on the front surface of the N-type semiconductor substrate 1.

A second dielectric layer 201, a first P+ doped layer 202, a secondpassivation layer 203, and a second electrode 204 are sequentiallyprovided on the back surface of the N-type semiconductor substrate 1.

The double-side passivation contact N-type solar cell is a back junctiondouble-side passivation contact N-type solar cell, in which the first N+doped layer 102 on the front surface and the N-type semiconductorsubstrate 1 (N-type silicon substrate) form an N+N junction. In a casewhere the first N+ doped layer is ultra-thin, a lower lateraltransmission resistance is achieved with the aid of the N-type siliconsubstrate. Moreover, the first P+ doped layer 202 is provided on theback surface to form a back emitter, and a thicker P+ doped layer 202(e.g., a conventional thickness of the P+ doped layer) can be adoptedwithout affecting light absorption of the cell. The N+N junction refersto a high-low junction formed by an N+ doped semiconductor materiallayer heavily doped and an N-type semiconductor substrate.

Therefore, in the back junction double-side passivation contact N-typesolar cell according to the embodiments of the present disclosure, theN+N high-low junction can assist in the lateral transmission of carriersby means of the substrate material, and a front-side passivation contactcan be achieved with a ultra-thin doped polycrystalline silicon having ahigh square resistance, which can avoid the light absorption problem ofthe existing ITO or a thick doped polycrystalline silicon, and alleviatea compromise restriction between lateral transmission and lightabsorption of a polycrystalline silicon film when the passivationcontact structure is applied to the front side of the cell, therebyincreasing a short-circuit current of the cell while achieving a highopen-circuit voltage. Moreover, a burn-through damage to the ultra-thinpassivation contact caused by the high-temperature metal slurry is alsoalleviated. For example, at least two passivation contact structures(e.g., the passivation contact structure illustrated in FIG. 2 or FIG.3) can be used for forming a front-side emission junction.

In some embodiments of the present disclosure, each of the front andback surfaces of the N-type semiconductor substrate 1 may be a texturedsurface with extremely uneven surface morphology. The textured surfacemay include a perforated rough surface formed through regular pyramid,inverted pyramid, reactive ion etching (ME) or Metal Catalyst AssistedTexturing (MCT).

In some embodiments of the present disclosure, the surface of thesemiconductor substrate has a textured structure formed throughtexturing, which produces a light trapping effect, and increases theamount of light absorbed by the solar cell, improving conversionefficiency of the solar cell.

In some embodiments of the present disclosure, a thickness of the N-typesemiconductor substrate 1 may be in a range from 100 μm to 300 μm,optionally in a range from 100 μm to 250 μm, more optionally in a rangefrom 120 μm to 240 μm, e.g., 100 μm, 120 μm, 150 μm, 180 μm, 200 μm, 240μm, 250 μm, 280 μm, 300 μm, or other values within these ranges, whichare not limited herein.

The specific types of the first dielectric layer 101 and the seconddielectric layer 201 are varied and can be selected according to actualrequirements, which is not limited in the present disclosure. Forexample, in some embodiments of the present disclosure, the firstdielectric layer 101 may include at least one of silicon oxide, hafniumoxide, titanium oxide, silicon nitride, silicon oxynitride, or aluminumoxide. For example, the first dielectric layer 101 may be a silicondioxide dielectric layer, a silicon nitride dielectric layer, analuminum oxide dielectric layer, a hafnium oxide dielectric layer, atitanium oxide dielectric layer, or a silicon oxynitride dielectriclayer, or other dielectric layers known or newly developed in the art.For example, in some other embodiments of the present disclosure, thefirst dielectric layer 101 may also be a dielectric layer doped withphosphorus or other elements.

Accordingly, in some embodiments of the present disclosure, the seconddielectric layer 201 includes at least one of silicon oxide, hafniumoxide, titanium oxide, silicon nitride, silicon oxynitride, or aluminumoxide. For example, the second dielectric layer 201 may be a silicondioxide dielectric layer, a silicon nitride dielectric layer, analuminum oxide dielectric layer, a hafnium oxide dielectric layer, atitanium oxide dielectric layer, or a silicon oxynitride dielectriclayer, or other dielectric layers known or newly developed in the art.For example, in some other embodiments of the present disclosure, thesecond dielectric layer 201 may be a dielectric layer doped with otherelements.

In some embodiments of the present disclosure, the first dielectriclayer 101 may be a tunnel oxide layer, and the second dielectric layer201 may be a tunnel oxide layer.

In some embodiments of the present disclosure, a thickness of the firstdielectric layer 101 may be in a range from 0.5 nm to 3 nm, optionallyin a range from 1.0 nm to 2.5 nm, e.g., 0.5 nm, 0.8 nm, 1 nm, 1.5 nm, 2nm, 2.5 nm, or 3 nm, etc.

In some embodiments of the present disclosure, a thickness of the seconddielectric layer 201 may be in a range from 0.5 nm to 3 nm, optionallyin a range from 1.0 nm to 2.5 nm, e.g., 0.5 nm, 0.8 nm, 1 nm, 1.5 nm, 2nm, 2.5 nm, or 3 nm, etc.

The first dielectric layer 101 and second dielectric layer 201 arerequired to have tunnel effect that allows carriers in the substrate toenter the first N+ doped layer 102 and the first P+ doped layer 202(i.e., the doped polycrystalline silicon layers as illustrated below)while having a passivation effect on the surface of the semiconductorsubstrate. When the thickness of the dielectric layer is too small, thepassivation effect cannot be achieved. When the thickness of thedielectric layer is too large, the carriers cannot tunnel through thedoped polycrystalline silicon layers effectively.

In this N-type solar cell, a PN junction is located at the back side ofthe cell, that is, a back junction structure design is used. The firstN+ doped layer 102 and the N-type semiconductor substrate 1 form an N+Nhigh-low junction at the front side of the cell. With the passivationcontact structures on both the front and back sides of the cell, it isbeneficial to increase the open-circuit voltage of the cell and increasethe short-circuit current. The first N+ doped layer 102 may be, but isnot limited to, a first N+ doped polycrystalline silicon layer, in whicha dopant doped may be, for example, N-type elements such as phosphorus,arsenic, and antimony. The first P+ doped layer 202 may be, but is notlimited to, a first P+ doped polycrystalline silicon layer, in which adopant doped may be, for example, P-type elements such as boron, indium,gallium, and aluminum.

In some embodiments of the present disclosure, a doping concentration ofthe first N+ doped layer 102 may be in a range from 5×10¹⁹ cm⁻³ to6×10²⁰ cm⁻³, e.g., 5×10¹⁹ cm⁻³, 6×10¹⁹ cm⁻³, 7×10¹⁹ cm⁻³, 8×10¹⁹ cm⁻³,9×10¹⁹ cm⁻³, 1×10²⁰ cm⁻³, 2×10²⁰ cm⁻³, 4×10²⁰ cm⁻³, 5×10²⁰ cm⁻³, 6×10²⁰cm⁻³, or other values within the range.

In some embodiments of the present disclosure, a thickness of the firstN+ doped layer 102 may be in a range from 5 nm to 30 nm, e.g., 5 nm, 8nm, 10 nm, 15 nm, 18 nm, 20 nm, 22 nm, 25 nm, 30 nm, or other valueswithin the range.

With the doping concentration of the first N+ doped layer 102 controlledwithin the above range, the manufactured solar cell can meet itsperformance requirements, improving photoelectric conversion efficiencyof the solar cell and performance of the solar cell. Moreover, with arelatively small thickness of the first N+ doped layer 102, optionallyin a range from 5 nm to 30 nm, an ultra-thin doped polycrystallinesilicon having a high square resistance, when used for passivation andcontact, can avoid the light absorption problem of the existing ITO orthick polycrystalline silicon.

In some embodiments of the present disclosure, a doping concentration ofthe first P+ doped layer 202 may be in a range from 5×10¹⁹ cm⁻³ to6×10²⁰ cm⁻³. For example, the doping concentration of the first P+ dopedlayer 202 may be 5×10¹⁹ cm⁻³, 6×10¹⁹ cm⁻³, 7×10¹⁹ cm⁻³, 8×10¹⁹ cm⁻³,9×10¹⁹ cm⁻³, 1×10²⁰ cm⁻³, 2×10²⁰ cm⁻³, 4×10²⁰ cm⁻³, 5×10²⁰ cm⁻³, 6×10²⁰cm⁻³, or other values within this range.

In some embodiments of the present disclosure, a thickness of the firstP+ doped layer 202 may be in a range from 80 nm to 300 nm, e.g., 80 nm,100 nm, 150 nm, 180 nm, 200 nm, 220 nm, 250 nm, 280 nm, 300 nm, or othervalues within this range.

With the dopant concentration of the first P+ doped layer 202 controlledwithin the above range, the manufactured solar cell can meet itsperformance requirements, improving photoelectric conversion efficiencyof the solar cell and performance of the solar cell. Moreover, since thethickness of the first P+ doped layer 202 is moderate, optionally in arange from 80 nm to 300 nm, a relatively thick P+ doped polycrystallinesilicon layer can be adopted to form a back side emitter with the N-typesilicon substrate at the back side of the cell, without affecting lightabsorption of the cell.

In some embodiments of the present disclosure, the first passivationlayer 103 includes, but is not limited to, a stacked structure formed byone or more of silicon nitride, silicon oxide, silicon oxynitride, orsilicon carbide. The stacked structure refers to a structure thatincludes a plurality of sub-layers, each sub-layer including one or moreof silicon nitride, silicon oxide, silicon oxynitride, or siliconcarbide. It is noted that, the first passivation layer and the firstanti-reflection layer may also be made of other types of materials suchas aluminum oxide and amorphous silicon. In some embodiments of thepresent disclosure, the first passivation layer 103 may include a firstpassivation sub-layer that mainly plays a role of passivation and afirst anti-reflection sub-layer that mainly plays a role ofanti-reflection.

In some embodiments of the present disclosure, the second passivationlayer 203 includes, but is not limited to, a stacked structure formed byone or more of silicon nitride, silicon oxide, silicon oxynitride, orsilicon carbide. Herein, the stacked structure refers to a structurethat includes a plurality of sub-layers, each sub-layer including one ormore of silicon nitride, silicon oxide, silicon oxynitride, or siliconcarbide. It is noted that, the second passivation layer and the secondanti-reflection layer may also be made of other types of materials suchas aluminum oxide and amorphous silicon.

According to the embodiments of the present disclosure, the firstpassivation layer (or referred to as a first passivation layer in someembodiments) is a front-side passivation layer (or referred to as afront-side anti-reflection layer in some embodiments). The front-sidepassivation layer can be composed of stacked films. The stacked film mayinclude aluminum oxide, silicon oxide, silicon oxynitride, siliconnitride, gallium oxide, silicon carbide, amorphous silicon, siliconoxycarbide, or the like, or any combinations thereof. In addition, thefront-side passivation layer may contain materials of other types, whichare not limited in the present disclosure. The passivation layermentioned above has a good passivation effect on the semiconductorsubstrate, and is beneficial to improve conversion efficiency of thecell. A purpose of providing the anti-reflection layer is, on the onehand, to reduce reflection of light and increase amount of lightabsorbed by the solar cell, and on the other hand, to have a passivationeffect, thereby improving efficiency of the solar cell. Correspondingly,the second passivation layer mentioned above (or referred to as a secondanti-reflection layer in some embodiments) is a back-side passivationlayer (or referred to as a back-side anti-reflection layer in someembodiments). Similarly, the back-side passivation layer may be composedof stacked films, and the stacked film may include aluminum oxide,silicon oxide, silicon oxynitride, silicon nitride, gallium oxide,silicon carbide, amorphous silicon, silicon oxycarbide, or the like, orany combination thereof, which is not limited herein.

The back-side passivation layer and the back-side reflection layer maybe understood in the same way as the front-side structures (i.e., thefront-side passivation layer and the front-side anti-reflection layer),in terms of their main roles and functions, which will not be repeatedhere.

In some embodiments of the present disclosure, a thickness of the firstpassivation layer 103 may be in a range from 70 nm to 180 nm, e.g., 70nm, 80 nm, 90 nm, 100 nm, 120 nm, 140 nm, 150 nm, 160 nm, 180 nm, orother values within this range.

In some embodiments of the present disclosure, a thickness of the secondpassivation layer 203 may be in a range from 70 nm to 180 nm, e.g., 70nm, 80 nm, 90 nm, 100 nm, 120 nm, 140 nm, 150 nm, 160 nm, 180 nm, orother values within this range.

With the thicknesses of the passivation layer (or referred to as theanti-reflection layer) within the ranges mentioned above, it isbeneficial to have a good passivation effect and an anti-reflectioneffect.

The first electrode 104 mentioned above is a metal electrode composed ofa conductive material. The first electrode 104 penetrates through thefront-side anti-reflection layer and the front-side passivation layer tobe in contact with the first N+ doped layer, and is configured tocollect and export photocarriers. The second electrode 204 mentionedabove is a metal electrode composed of a conductive material. The secondelectrode 204 penetrates through the back-side reflection layer and theback-side passivation layer to in contact with the first P+ doped layer,and is configured to collect and export photocarriers. It should benoted that the materials of the first electrode 104 and the secondelectrode 204 are not limited in the present disclosure, and may be, forexample, a silver electrode, an aluminum electrode, or a silver-aluminumelectrode.

As shown in FIG. 2, based on the embodiments mentioned above, thedouble-side passivation contact N-type solar cell further includes athird dielectric layer 105 and a second N+ doped layer 106. In someembodiments of the present disclosure, at least one region on thesurface of the first N+ doped layer 102 is sequentially provided with athird dielectric layer 105 and a second N+ doped layer 106, and thefirst electrode 104 penetrates through the first passivation layer 103to be in contact with the second N+ doped layer 106. The at least oneregion on the surface of the first N+ doped layer 102 corresponds to aregion of the first electrode 104. For example, each of the at least oneregion on the surface of the first N+ doped layer 102 corresponds to aregion of one first electrode 104.

In this double-side passivation contact N-type solar cell, a regioncorresponding to the first electrode 104 is provided with the thirddielectric layer 105 and the second N+ doped layer 106, which not onlyincreases the open-circuit voltage and short-circuit current, but alsohelps to solve the burn-through damage problem of the ultra-thinpassivation contact caused by the high-temperature metal slurry.

In some embodiments of the present disclosure, the third dielectriclayer 105 includes, but is not limited to, at least one of siliconoxide, hafnium oxide, titanium oxide, silicon nitride, siliconoxynitride, or aluminum oxide. For example, the third dielectric layer105 may be a silicon dioxide dielectric layer, a silicon nitridedielectric layer, an aluminum oxide dielectric layer, a hafnium oxidedielectric layer, a titanium oxide dielectric layer, or a siliconoxynitride dielectric layer, or other dielectric layers known or newlydeveloped in the art.

It should be noted that the method of forming the dielectric layer isnot limited in the present disclosure. For example, a method of formingthe first dielectric layer and the third dielectric layer includes, butis not limited to, any one or more of chemical vapor deposition method,high-temperature thermal oxygen oxidation method, and nitric acidoxidation method.

In some embodiments of the present disclosure, a thickness of the thirddielectric layer 105 may be in a range from 0.5 nm to 3 nm, optionallyin a range from 1.0 nm to 2.5 nm, e.g., 0.5 nm, 0.8 nm, 1 nm, 1.5 nm, 2nm, 2.5 nm, or 3 nm.

In some embodiments of the present disclosure, a thickness of the secondN+ doped layer 106 may be in a range from 50 nm to 150 nm, e.g., 50 nm,60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 120 nm, 140 nm, 150 nm, or othervalues within this range. The thickness of the second N+ doped layer 106is required to be greater than that of the first N+ doped layer, inorder to meet performance requirements of the solar cell and improveperformance of the solar cell.

It should be noted that the method of forming the N+ doped layer is notlimited in the present disclosure. For example, a method of forming thefirst N+ doped layer 102 and the second N+ doped layer 106 includes, butis not limited to, chemical vapor deposition (CVD), physical vapordeposition (PVD), or atomic layer deposition (ALD), e.g., plasmaenhanced chemical vapor deposition (PECVD), low pressure chemical vapordeposition (LPCVD), or the like. In addition, the third dielectric layerand the second N+ doped layer can be formed by means of a patternedmask.

As shown in FIG. 3, based on the embodiments mentioned above, thedouble-side passivation contact N-type solar cell may further have athickened N+ doped region 107. In some embodiments of the presentdisclosure, at least one region of the first N+ doped layer 102 isformed as a thickened N+ doped region 107, and the first electrode 104penetrates through the first passivation layer 103 to be in contact withthe thickened N+ doped region 107. The at least one region of the firstN+ doped layer 102 corresponds to a region of the first electrode 104.

In this double-side passivation contact N-type solar cell, a regioncorresponding to the first electrode 104 is provided with the thickenedN+ doped region 107, which not only increases the open-circuit voltageand short-circuit current, but also helps to solve a burn-through damageproblem of the ultra-thin passivation contact caused by thehigh-temperature metal slurry.

In some embodiments of the present disclosure, a thickness of thethickened N+ doped region 107 may be in a range from 80 nm to 200 nm,e.g., 80 nm, 90 nm, 100 nm, 120 nm, 140 nm, 150 nm, 160 nm, 180 nm, 200nm, or other values within this range.

It can be understood that the first N+ doped layer 102 may have an N+doped region with a normal thickness and a thickened N+ doped region107. The normal thickness of the N+ doped region may be in a range from5 nm to 30 nm. The thickness of the thickened N+ doped region 107 may bein a range from 80 nm to 200 nm. The thickness of the thickened N+ dopedregion corresponds to a region of the first electrode.

[P-Type Solar Cell]

Referring to FIGS. 4-6, some embodiments of the present disclosureprovides a solar cell, i.e., a double-side passivation contact P-typesolar cell, including a P-type semiconductor substrate 2.

The P-type semiconductor substrate 2 includes a first surface 10 and asecond surface 20 that are opposite to each other. The first surface 10is a back surface of the semiconductor substrate, and the second surface20 is a front surface of the semiconductor substrate.

A second dielectric layer 201, a first P+ doped layer 202, a secondpassivation layer 203, and a second electrode 204 are sequentiallyprovided on the front surface of the P-type semiconductor substrate 2.

A first dielectric layer 101, a first N+ doped layer 102, a firstpassivation layer 103, and a first electrode 104 are sequentiallyprovided on the back surface of the P-type semiconductor substrate 2.

The double-side passivation contact P-type solar cell is a back junctiondouble-side passivation contact P-type solar cell, in which the first P+doped layer 202 on the front surface and the P-type semiconductorsubstrate 2 (P-type silicon substrate) form an P+P junction. In a casewhere the first P+ doped layer is ultra-thin, a lower lateraltransmission resistance is achieved with the aid of the P-type siliconsubstrate. Moreover, the first N+ doped layer 102 is used on the backsurface to form a back emitter, and a thicker N+ doped layer (e.g., witha conventional thickness of the N+ doped layer) may not be adoptedwithout affecting light absorption of the cell. The P+P junction refersto a high-low junction formed by a P+ doped semiconductor material layerheavily doped and a P-type semiconductor substrate.

Therefore, in the back junction double-side passivation contact P-typesolar cell according to the embodiments of the present disclosure, theP+P high-low junction can assist in the lateral transmission of carriersby means of the substrate material, and a front-side passivation contactcan be achieved using an ultra-thin doped polycrystalline silicon havinga high square resistance, which avoids the light absorption of theexisting ITO or thick doped polycrystalline silicon, and alleviates acompromise restriction between lateral transmission and light absorptionof a polycrystalline silicon film when a passivation contact structureis applied to the front side of the cell, thereby increasing ashort-circuit current of the cell while achieving a high open-circuitvoltage. In addition, the burn-through damage problem of the ultra-thinpassivation contact caused by the high-temperature metal slurry is alsoalleviated. For example, at least two passivation contact structures(e.g., the passivation contact structure illustrated in FIG. 5 or FIG.6) can be used for forming a front-side emission junction.

In some embodiments of the present disclosure, each of the front andback surfaces of the P-type semiconductor substrate 2 may be a texturedsurface with extremely uneven surface morphology. The textured surfacemay include a perforated rough surface manufactured by a method ofregular pyramid, inverted pyramid, reactive ion etching (ME) or MetalCatalyst Assisted Texturing (MCT). In some embodiments of the presentdisclosure, the surface of the semiconductor substrate has a texturedstructure formed through texturing, which produces a light trappingeffect, and increases the amount of light absorbed by the solar cell,improving conversion efficiency of the solar cell.

In some embodiments of the present disclosure, a thickness of the P-typesemiconductor substrate 2 may be in a range from 100 μm to 300 μm,optionally in a range from 100 μm to 250 μm, more optionally in a rangefrom 120 μm to 240 μm, e.g., 100 μm, 120 μm, 150 μm, 180 μm, 200 μm, 240μm, 250 μm, 280 μm, 300 μm, or other values within these ranges, whichare not limited herein.

In this P-type solar cell, the specific types of the second dielectriclayer 201 and the first dielectric layer 101 are not limited in thepresent disclosure, and can be selected according to actualrequirements. In some embodiments of the present disclosure, the seconddielectric layer 201 and the first dielectric layer 101 each include,but are not limited to, at least one of silicon oxide, hafnium oxide,titanium oxide, silicon nitride, silicon oxynitride, or aluminum oxide.For example, it can be a silicon dioxide dielectric layer, a siliconnitride dielectric layer, an aluminum oxide dielectric layer, a hafniumoxide dielectric layer, a titanium oxide dielectric layer, or a siliconoxynitride dielectric layer, or other dielectric layers known or newlydeveloped in the art. In addition, in some embodiments of the presentdisclosure, the second dielectric layer 201 and the first dielectriclayer 101 may be dielectric layers doped with phosphorus or otherelements.

In some embodiments of the present disclosure, the second dielectriclayer 201 may be a tunnel oxide layer, and the first dielectric layer101 may be a tunnel oxide layer.

In some embodiments of the present disclosure, a thickness of the seconddielectric layer 201 may be in a range from 0.5 nm to 3 nm, optionallyin a range from 1.0 nm to 2.5 nm, e.g., 0.5 nm, 0.8 nm, 1 nm, 1.5 nm, 2nm, 2.5 nm, or 3 nm. A thickness of the first dielectric layer 101 maybe in a range from 0.5 nm to 3 nm, optionally in a range from 1.0 nm to2.5 nm, e.g., 0.5 nm, 0.8 nm, 1 nm, 1.5 nm, 2 nm, 2.5 nm, or 3 nm. Thesecond dielectric layer 201 and the first dielectric layer 101 arerequired to have tunnel effect that allow carriers in the semiconductorsubstrate to enter the first P+ doped layer 202 and the first N+ dopedlayer 102 while having a passivation effect on the surface of thesemiconductor substrate. When the thickness of the dielectric layer istoo small, the passivation effect cannot be achieved. When the thicknessof the dielectric layer is too large, carriers cannot tunnel through thesecond dielectric layer 201 and the first dielectric layer 101effectively.

In this P-type solar cell, the PN junction is located at the back sideof the cell, that is, a back junction structure design is used. Thefirst P+ doped layer 202 and the P-type semiconductor substrate 2 form aP+P high-low junction at the front side of the cell. The passivationcontact structure on both the front and back sides of the cell isbeneficial to increase the open-circuit voltage of the cell and increasethe short-circuit current. The first P+ doped layer 202 may be, but isnot limited to, a first P+ doped polycrystalline silicon layer, in whichthe dopant doped may be, for example, P-type elements such as boron,indium, gallium, and aluminum. The first N+ doped layer 102 may be, butis not limited to, a first N+ doped polycrystalline silicon layer, inwhich the dopant doped may be, for example, N-type elements such asphosphorus, arsenic, and antimony.

In some embodiments of the present disclosure, in the P-type solar cell,a doping concentration of the first P+ doped layer 202 may be in a rangefrom 5×10¹⁹ cm⁻³ to 6×10²⁰ cm⁻³, e.g., 5×10¹⁹ cm⁻³, 6×10¹⁹ cm⁻³, 7×10¹⁹cm⁻³, 8×10¹⁹ cm⁻³, 9×10¹⁹ cm⁻³, 1×10²⁰ cm⁻³, 2×10²⁰ cm⁻³, 4×10²⁰ cm⁻³,5×10²⁰ cm⁻³, 6×10²⁰ cm⁻³, or other values within this range. In someembodiments of the present disclosure, a thickness of the first P+ dopedlayer 202 may be in a range from 5 nm to 30 nm, e.g., 5 nm, 8 nm, 10 nm,15 nm, 18 nm, 20 nm, 22 nm, 25 nm, 30 nm, or other values within thisrange.

With the dopant concentration of the first P+ doped layer 202 controlledwithin the above range, the manufactured solar cell can meet itsperformance requirements, improving photoelectric conversion efficiencyof the solar cell and performance of the solar cell. Moreover, thethickness of the first P+ doped layer 202 is relatively small,optionally in a range from 5 nm to 30 nm, and passivation and contactcan be achieved by using an ultra-thin doped polycrystalline siliconhaving a high square resistance, avoiding the light absorption problemof the existing ITO or thick polycrystalline silicon.

In some embodiments of the present disclosure, in the P-type solar cell,a doping concentration of the first N+ doped layer 102 may be in a rangefrom 5×10¹⁹ cm⁻³ to 6×10²⁰ cm⁻³, e.g., 5×10¹⁹ cm⁻³, 6×10¹⁹ cm⁻³, 7×10¹⁹cm⁻³, 8×10¹⁹ cm⁻³, 9×10¹⁹ cm⁻³, 1×10²⁰ cm⁻³, 2×10²⁰ cm⁻³, 4×10²⁰ cm⁻³,5×10²⁰ cm⁻³, 6×10²⁰ cm⁻³, or other values within this range. In someembodiments of the present disclosure, a thickness of the first N+ dopedlayer 102 may be in a range from 80 nm to 300 nm, e.g., 80 nm, 100 nm,150 nm, 180 nm, 200 nm, 220 nm, 250 nm, 280 nm, 300 nm, or other valueswithin this range.

With the dopant concentration of the first N+ doped layer 102 controlledwithin the above range, the manufactured solar cell can meet itsperformance requirements, improving photoelectric conversion efficiencyof the solar cell and performance of the solar cell. Moreover, since thethickness of the first N+ doped layer 102 is moderate, optionally in arange from 80 nm to 300 nm, a thicker N+ doped polycrystalline siliconlayer can be used to form a back-side emitter with the P-type siliconsubstrate at the back side of the cell, without affecting lightabsorption of the cell.

In some embodiments of the present disclosure, in the P-type solar cell,the second passivation layer 203 includes, but is not limited to, astacked structure formed by one or more of silicon nitride, siliconoxide, silicon oxynitride, or silicon carbide. The stacked structurerefers to a structure that includes a plurality of sub-layers, eachsub-layer including one or more of silicon nitride, silicon oxide,silicon oxynitride, or silicon carbide. It is noted that, the secondpassivation layer and the second anti-reflection layer may be made ofother types of materials such as aluminum oxide and amorphous silicon.In some embodiments of the present disclosure, the second passivationlayer includes a second passivation sub-layer that mainly plays a roleof passivation and a second anti-reflection sub-layer that mainly playsa role of anti-reflection.

Correspondingly, the first passivation layer 103 includes, but is notlimited to, a stacked structure formed by one or more of siliconnitride, silicon oxide, silicon oxynitride, or silicon carbide. It isnoted that, the first passivation layer and the first anti-reflectionlayer may be made of other types of materials such as aluminum oxide andamorphous silicon.

In the P-type solar cell according to the embodiments of the presentdisclosure, the second passivation layer is a front-side passivationlayer, and the second anti-reflection layer is a front-sideanti-reflection layer. The first passivation layer is a back-sidepassivation layer, and the first anti-reflection layer is a back-sideanti-reflection layer. The specific materials, main roles and functionsof the front-side passivation layer, the front-side anti-reflectionlayer, the back-side passivation layer, and the back-sideanti-reflection layer can be referred to the description of thecorresponding part of the N-type solar cell mentioned above, which willnot be repeated here.

In some embodiments of the present disclosure, a thickness of the secondpassivation layer 203 may be in a range from 70 nm to 180 nm, e.g., 70nm, 80 nm, 90 nm, 100 nm, 120 nm, 140 nm, 150 nm, 160 nm, 180 nm, orother values within this range. A thickness of the first passivationlayer 103 may be in a range from 70 nm to 180 nm, e.g., 70 nm, 80 nm, 90nm, 100 nm, 120 nm, 140 nm, 150 nm, 160 nm, 180 nm, or other valueswithin this range. The above thickness ranges of the passivation layerand the anti-reflection layer can bring about a good passivation effectand an anti-reflection effect.

As described above, the specific materials of the second electrode 204and the first electrode 104 are not limited here, and may be, forexample, a silver electrode, an aluminum electrode, or a silver-aluminumelectrode.

As shown in FIG. 5, based on the embodiments mentioned above, thedouble-side passivation contact P-type solar cell further includes afourth dielectric layer 205 and a second P+ doped layer 206. In someembodiments of the present disclosure, at least one region on thesurface of the first P+ doped layer 202 is further provided with afourth dielectric layer 205 and a second P+ doped layer 206, and thesecond electrode 204 penetrates through the second passivation layer 203to be in contact with the second P+ doped layer 206. The at least oneregion on the surface of the first P+ doped layer 202 corresponds to aregion of the second electrode 204. For example, each of at least oneregion on the surface of the first P+ doped layer 202 corresponds to aregion of one second electrode 204.

In this double-side passivation contact P-type solar cell, a regioncorresponding to the second electrode 204 is provided with the fourthdielectric layer 205 and the second P+ doped layer 206, which not onlyincreases the open-circuit voltage and short-circuit current, but alsohelps to solve a burn-through damage problem of the ultra-thinpassivation contact caused by the high-temperature metal slurry.

In some embodiments of the present disclosure, the fourth dielectriclayer 205 includes at least one of silicon oxide, hafnium oxide,titanium oxide, silicon nitride, silicon oxynitride, or aluminum oxide.A thickness of the fourth dielectric layer 205 may be in a range from0.5 nm to 3 nm.

The fourth dielectric layer 205 is similar to the third dielectric layer105 mentioned above. The specific type and forming method of the fourthdielectric layer 205 can be referred to the description of the thirddielectric layer 105 mentioned above, which will not be elaborated here.

In some embodiments of the present disclosure, a thickness of the secondP+doped layer 206 may be in a range from 50 nm to 150 nm, e.g., 50 nm,60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 120 nm, 140 nm, 150 nm, or othervalues within this range. The thickness of the second P+ doped layer 206is required to be greater than the thickness of the first P+ doped layer202, which is beneficial to meet performance requirements of the solarcell and improve performance of the solar cell.

As shown in FIG. 6, based on the embodiments mentioned above, thedouble-side passivation contact P-type solar cell may further have athickened P+ doped region 207. In some embodiments of the presentdisclosure, at least one region of the first P+ doped layer 202 isformed as the thickened P+ doped region 207, and the second electrode204 penetrates through the second passivation layer 203 to be in contactwith the thickened P+ doped region 207. The at least one region of thefirst P+ doped layer 202 corresponds to a region of the second electrode204.

In this structure of the double-side passivation contact P-type solarcell, a region corresponding to the second electrode 204 is providedwith the thickened P+ doped region 207, which not only increases theopen-circuit voltage and short-circuit current, but also a helps tosolve the burn-through damage problem of the ultra-thin passivationcontact caused by the high-temperature metal slurry.

In some embodiments of the present disclosure, a thickness of thethickened P+ doped region 207 may be in a range from 80 nm to 200 nm,e.g., 80 nm, 90 nm, 100 nm, 120 nm, 140 nm, 150 nm, 160 nm, 180 nm, 200nm, or other values within this range.

It can be understood that the first P+ doped layer 202 may have a P+doped region with a normal thickness and a thickened P+ doped region207. The normal thickness of the P+ doped region may be in a range from5 nm to 30 nm. The thickness of the thickened P+ doped region 207 may bein a range from 80 nm to 200 nm. The thickness of the thickened P+ dopedregion corresponds to a region of the second electrode.

Embodiments of the present disclosure also provide a photovoltaic moduleincluding solar cells mentioned above, and at least part of the solarcells is connected to each other in a splicing or stacking manner andsealed by an encapsulating material.

In some embodiments of the present disclosure, the photovoltaic moduleis formed by a plurality of solar cells which is located in the sameplane and electrically connected to each other with a gap (small gap) orwithout gap. In some embodiments of the present disclosure, thephotovoltaic module is formed by a plurality of solar cells which iselectrically connected to each other in a stacking manner (that is,located in different planes). The solar cell can be any cell asdescribed in FIGS. 1-6.

Those skilled in the art can understand that the photovoltaic module andthe solar cell mentioned above are based on the same invention concept.The features and advantages described above for the solar cell can alsoapply to the photovoltaic module of the present disclosure. Therefore,the photovoltaic module at least has the same features and advantages asthe solar cells mentioned above, which will not be elaborated here.

For example, the photovoltaic module may sequentially include, frombottom to top, a back plate, an encapsulating material, a cell string,an encapsulating material, and glass. The encapsulating material can beEVA, POE, and other encapsulating film materials well-known in the art.The cell string may be formed by the solar cells mentioned above in asplicing or stacking manner, and a gap may be present between the cellsof the cell string formed in a splicing manner.

The above illustrates several embodiments of the present disclose, whichis not intended to limit the present disclosure. Changes andmodifications may be made by those skilled in the art without departingfrom the scope of the present disclosure. Whatever within the principlesof the present disclosure, including any modification, equivalentsubstitution, improvement, etc., shall fall into the protection scope ofthe present disclosure.

It should be pointed out that the present disclosure contains somecontents protected by copyright. Except for making copies of the patentdocuments or the contents of the recorded patent documents of the PatentOffice, the copyright owner reserves the copyright.

What is claimed is:
 1. A solar cell, comprising: a N-type semiconductorsubstrate comprising a first surface and a second surface that areopposite to each other; a first dielectric layer located on the firstsurface; a first N+ doped layer located on a surface of the firstdielectric layer; a first passivation layer located on a surface of thefirst N+ doped layer; a first electrode located on a surface of thefirst passivation layer; a second dielectric layer located on the secondsurface; a first P+ doped layer located on a surface of the seconddielectric layer; a second passivation layer located on a surface of thefirst P+ doped layer; and a second electrode located on a surface of thesecond passivation layer, wherein the semiconductor substrate is anN-type semiconductor substrate, the first surface is a front surface ofthe semiconductor substrate, and the second surface is a back surface ofthe semiconductor substrate, wherein at least one region on the surfaceof the first N+ doped layer is further provided with a third dielectriclayer and a second N+ doped layer, and the first electrode penetratesthrough the first passivation layer to be in contact with the second N+doped layer, wherein at least one region of the first N+ doped layer isformed as a thickened N+ doped region, and the first electrodepenetrates through the first passivation layer to be in contact with thethickened N+ doped region, and wherein the at least one region of thefirst N+ doped layer corresponds to a region of the first electrode. 2.The solar cell according to claim 1, wherein a thickness of the secondN+ doped layer is greater than a thickness of the first N+ doped layer,and wherein the first dielectric layer has a different thickness fromthe second dielectric layer.
 3. The solar cell according to claim 1,wherein the second N+ doped layer has a thickness in a range from 50 nmto 150 nm.
 4. The solar cell according to claim 1, wherein the thickenedN+ doped region has a thickness in a range from 80 nm to 200 nm.
 5. Thesolar cell according to claim 1, wherein the first dielectric layercomprises at least one of silicon oxide, hafnium oxide, titanium oxide,silicon nitride, silicon oxynitride, or aluminum oxide; and the firstdielectric layer has a thickness in a range from 0.5 nm to 3 nm.
 6. Thesolar cell according to claim 1, wherein the first N+ doped layer has athickness in a range from 5 nm to 30 nm.
 7. The solar cell according toclaim 1, wherein the first passivation layer comprises at least one ofsilicon nitride, silicon oxide, silicon oxynitride, or silicon carbide;and the first passivation layer has a thickness in a range from 70 nm to180 nm.
 8. The solar cell according to claim 1, wherein the seconddielectric layer comprises at least one of silicon oxide, hafnium oxide,titanium oxide, silicon nitride, silicon oxynitride, or aluminum oxide;and the second dielectric layer has a thickness in a range from 0.5 nmto 3 nm.
 9. The solar cell according to claim 1, wherein the first P+doped layer has a doping concentration in a range from 5×10¹⁹ cm⁻³ to6×10²⁰ cm⁻³; and the first P+ doped layer has a thickness in a rangefrom 80 nm to 300 nm.
 10. The solar cell according to claim 1, whereinthe second passivation layer comprises at least one of silicon nitride,silicon oxide, silicon oxynitride, or silicon carbide; and the secondpassivation layer have a thickness in a range from 70 nm to 180 nm. 11.A photovoltaic module, comprising solar cells, wherein at least part ofthe solar cells is connected to each other in a splicing or stackingmanner and sealed by an encapsulating material, wherein one of the solarcells comprises: a N-type semiconductor substrate comprising a firstsurface and a second surface that are opposite to each other; a firstdielectric layer located on the first surface; a first N+ doped layerlocated on a surface of the first dielectric layer; a first passivationlayer located on a surface of the first N+ doped layer; a firstelectrode located on a surface of the first passivation layer; a seconddielectric layer located on the second surface; a first P+ doped layerlocated on a surface of the second dielectric layer; a secondpassivation layer located on a surface of the first P+ doped layer; anda second electrode located on a surface of the second passivation layer,wherein the semiconductor substrate is an N-type semiconductorsubstrate, the first surface is a front surface of the semiconductorsubstrate, and the second surface is a back surface of the semiconductorsubstrate, wherein at least one region on the surface of the first N+doped layer is further provided with a third dielectric layer and asecond N+ doped layer, and the first electrode penetrates through thefirst passivation layer to be in contact with the second N+ doped layer,wherein at least one region of the first N+ doped layer is formed as athickened N+ doped region, and the first electrode penetrates throughthe first passivation layer to be in contact with the thickened N+ dopedregion, and wherein the at least one region of the first N+ doped layercorresponds to a region of the first electrode.
 12. The photovoltaicmodule according to claim 11, wherein a thickness of the second N+ dopedlayer is greater than a thickness of the first N+ doped layer, andwherein the first dielectric layer has a different thickness from thesecond dielectric layer.
 13. The photovoltaic module according to claim11, wherein the second N+ doped layer has a thickness in a range from 50nm to 150 nm.
 14. The photovoltaic module according to claim 11, whereinthe thickened N+ doped region has a thickness in a range from 80 nm to200 nm.
 15. The photovoltaic module according to claim 11, wherein thefirst dielectric layer comprises at least one of silicon oxide, hafniumoxide, titanium oxide, silicon nitride, silicon oxynitride, or aluminumoxide; and the first dielectric layer has a thickness in a range from0.5 nm to 3 nm.
 16. The photovoltaic module according to claim 11,wherein the first N+ doped layer has a thickness in a range from 5 nm to30 nm.
 17. The photovoltaic module according to claim 11, wherein thefirst passivation layer comprises at least one of silicon nitride,silicon oxide, silicon oxynitride, or silicon carbide; and the firstpassivation layer has a thickness in a range from 70 nm to 180 nm. 18.The photovoltaic module according to claim 11, wherein the seconddielectric layer comprises at least one of silicon oxide, hafnium oxide,titanium oxide, silicon nitride, silicon oxynitride, or aluminum oxide;and the second dielectric layer has a thickness in a range from 0.5 nmto 3 nm.
 19. The photovoltaic module according to claim 11, wherein thefirst P+ doped layer has a doping concentration in a range from 5×10¹⁹cm⁻³ to 6×10²⁰ cm⁻³; and the first P+ doped layer has a thickness in arange from 80 nm to 300 nm.
 20. The photovoltaic module according toclaim 11, wherein the second passivation layer comprises at least one ofsilicon nitride, silicon oxide, silicon oxynitride, or silicon carbide;and the second passivation layer have a thickness in a range from 70 nmto 180 nm.